Abstract
The effects of lithium (Li) doping concentration and gate dielectrics on the performance of solution-processed zinc-oxide (ZnO) thin-film transistors (TFTs) has been investigated. ZnO films with strong c-axis orientation and lower background conductivity was obtained with 15 at.% of Li. Different crystallization behavior of ZnO was observed in the case of various dielectric surfaces. The 15-at.% Li-doped ZnO films (thickness similar to 20 nm) prepared on SiO2 and SiNx were found to be present in crystalline form, whereas the film prepared on aluminum titanium oxide (ATO) was found to be amorphous. A field-effect mobility of 1.81 cm(2)/V-sec and an I-on/I-off ratio of 2 x 10(6) were obtained for the 15-at.% Li-doped ZnO TFTs with a bilayer gate dielectric of SiO2 and SiNx. The comparison of dielectric studies showed that the performance of TFTs prepared on SiNx and ATO are higher than that of the TFTs prepared on SiO2.